The horse was first domesticated around 4000 BC in the Ukraine. But horses were first used for pulling carts.
The ancient Iranians were among the first people who used horses for riding some time around 2000 BC.
This enabled them to move from Central Asia to today's Iran. Horses were very important for the ancient Iranians. They used them for their meat and for riding.
The ancient Iranians were also among the first people who bred large horses known as "wind foot."

The Avesta mentions 8 different breeds of horse including the Arab, the Persian, and the mule. One of the oldest horse breeds in the world is the Caspian horse (below), which has been living in Iran since at least 3000 BC.

The Caspian is the direct descendent of the horses used by the ancient Persians. The seal below shows King Darius the Great (522 BC-428 BC) riding a Caspian.
Unfortunately the Caspian is almost extinct in Iran. Today, there are only about 400 of them left mostly in Europe and the United States.

One of the horse species mentioned in the Avesta is the Persian onager (wild ass), which used to live in Iran. The onager (below) is a very fast animal. It can gallop at the speed of 30 mph (48 kph) and can jump almost 7 ft. (2m)!